Category: Etiology

Multiple chemical sensitivity in sick-building syndrome

Abstract:

The sick building syndrome includes irritation of the eyes and the respiratory tract neurotoxicity affectation and skin problems, which can occur in individuals under improperly ventilated buildings. Poor air quality, as shown in CO2 atmospheric levels of more than 1,000 ppm, results in a pathological exposure to biological and chemical products. We present a work-related case of multiple chemical hypersensitivity from a dialysis unit that had no air renewal. This person, who was summitted to continuous exposure despite having taken corrective measures in the ventilation, developed chronic fatigue syndrome. An acoustic voice observation alerted of the case which led to the analysis of the environmental conditions which confirmed the relationship between multiple chemical hypersensitivity and chronic fatigue syndrome. This case stresses the neglected fact that all health service centres pose a high risk of chemical exposure and that there exists a lack of rigoroursness in putting in practice scientific medical knowledge.

 

Source: Arnold Llamosas PA, Arrizabalaga Clemente P, Bonet Agusti M, de la Fuente Brull X. Multiple chemical sensitivity in sick-building syndrome. Med Clin (Barc). 2006 May 27;126(20):774-8. [Article in Spanish] https://www.ncbi.nlm.nih.gov/pubmed/16883665

 

Oxidative stress levels are raised in chronic fatigue syndrome and are associated with clinical symptoms

Abstract:

The aetiology of chronic fatigue syndrome (CFS) is unknown; however, recent evidence suggests excessive free radical (FR) generation may be involved. This study investigated for the first time levels of 8-iso-prostaglandin-F(2 alpha)-isoprostanes alongside other plasma markers of oxidative stress in CFS patients and control subjects.

Forty-seven patients (18 males, 29 females, mean age 48 [19–63] years) who fulfilled the Centres for Disease Control classification for CFS and 34 healthy volunteers (13 males, 21 females, 46 [19–63] years) were enrolled in the study. The CFS patients were divided into two groups; one group had previously defined cardiovascular (CV) risk factors of obesity and hypertension (group 1) and the second were normotensive and nonobese (group 2). Patients had significantly increased levels of isoprostanes (group 1, P=0.007; group 2, P=0.03, unpaired t test compared to controls) and oxidised low-density lipoproteins (group 2, P=0.02) indicative of a FR attack on lipids. CFS patients also had significantly lower high-density lipoproteins (group 1, P=0.011; group 2, P=0.005).

CFS symptoms correlated with isoprostane levels, but only in group 2 low CV risk CFS patients (isoprostanes correlated with; total symptom score P=0.005; joint pain P=0.002; postexertional malaise P=0.027, Pearson). This is the first time that raised levels of the gold standard measure of in vivo oxidative stress (isoprostanes) and their association with CFS symptoms have been reported.

 

Source: Kennedy G, Spence VA, McLaren M, Hill A, Underwood C, Belch JJ. Oxidative stress levels are raised in chronic fatigue syndrome and are associated with clinical symptoms. Free Radic Biol Med. 2005 Sep 1;39(5):584-9. http://www.ncbi.nlm.nih.gov/pubmed/16085177

 

Stress-associated changes in the steady-state expression of latent Epstein-Barr virus: implications for chronic fatigue syndrome and cancer

Abstract:

Antibodies to several Epstein-Barr virus (EBV)-encoded enzymes are observed in patients with different EBV-associated diseases. The reason for these antibody patterns and the role these proteins might play in the pathophysiology of disease, separate from their role in virus replication, is unknown.

In this series of studies, we found that purified EBV deoxyuridine triphosphate nucleotidohydrolase (dUTPase) can inhibit the replication of human peripheral blood mononuclear cells in vitro and upregulate the production of TNF-alpha, IL-1beta, IL-6, IL-8, and IL-10. It also enhanced the ability of natural killer cells to lyse target cells. The EBV dUTPase also significantly inhibited the replication of mitogen-stimulated lymphocytes and the synthesis of IFN-gamma by cells isolated from lymph nodes and spleens obtained from mice inoculated with the protein.

It also produced sickness behaviors known to be induced by some of the cytokines that were studied in the in vitro experiments. These symptoms include an increase in body temperature, a decrease in body mass and in physical activity.

The data provide a new perspective on how an early nonstructural EBV-encoded protein can cause immune dysregulation and produce clinical symptoms observed in patients with chronic fatigue syndrome (CFS) separate from its role in virus replication and may serve as a new approach to help identify one of the etiological agents for CFS. The data also provide additional insight into the pathophysiology of EBV infection, inflammation, and cancer.

 

Source: Glaser R, Padgett DA, Litsky ML, Baiocchi RA, Yang EV, Chen M, Yeh PE, Klimas NG, Marshall GD, Whiteside T, Herberman R, Kiecolt-Glaser J, Williams MV. Stress-associated changes in the steady-state expression of latent Epstein-Barr virus: implications for chronic fatigue syndrome and cancer. Brain Behav Immun. 2005 Mar;19(2):91-103. http://www.ncbi.nlm.nih.gov/pubmed/15664781

 

Childhood predictors of self reported chronic fatigue syndrome/myalgic encephalomyelitis in adults: national birth cohort study

Abstract:

OBJECTIVE: To study childhood risk factors for chronic fatigue syndrome in adult life.

DESIGN: Examination of data from the 1970 British birth cohort.

PARTICIPANTS: 16,567 babies born 5-11 April 1970, followed up at 5, 10, 16, and 29-30 years.

MAIN OUTCOME MEASURES: Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) identified by self report at age 30 years. Data from childhood from questionnaires given to parents and teachers. Maternal mental health assessed with the malaise inventory.

RESULTS: 93 (0.8%, 95% confidence interval 0.7 to 1.0) of 11 261 participants reported ever having CFS/ME, and 48 (0.4%, 0.3 to 0.6) had the condition currently. Higher risk of CFS/ME was associated with having a limiting longstanding condition in childhood (odds ratio 2.3, 1.4 to 3.9), female sex (2.3, 1.4 to 2.6), and high social class in childhood (2.2, 1.4 to 3.5). Higher levels of exercise in childhood were associated with lower risk (0.5, 0.2 to 0.9). Maternal psychological disorder, psychological problems in childhood, birth weight, birth order, atopy, obesity, school absence, academic ability, and parental illness were not associated with risk of CFS/ME.

CONCLUSIONS: We identified no association between maternal or child psychological distress, academic ability, parental illness, atopy, or birth order and increasing risk of lifetime CFS/ME. Sedentary behaviour increased the risk.

Comment in: What causes chronic fatigue syndrome? [BMJ. 2004]

 

Source: Viner R, Hotopf M. Childhood predictors of self reported chronic fatigue syndrome/myalgic encephalomyelitis in adults: national birth cohort study. BMJ. 2004 Oct 23;329(7472):941. Epub 2004 Oct 6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC524102/ (Full article)

 

 

Detection of antibody against Borna disease virus-p24 in the plasma of Chinese patients with chronic fatigue syndrome by Western-blot analysis

Abstract:

OBJECTIVE: To evaluate the prevalence of infection with Borna disease virus (BDV) in Chinese patients with chronic fatigue syndrome (CFS) and control subjects, and to discuss the etiological association between CFS and infection with BDV.

METHODS: The CDC (1994) diagnostic criteria for CFS were used for case definition. Sixty-one patients suffered from CFS were from 11 Provinces in China. To detect the antibody against BDV-p24 on the plasma samples from all cases and 73 healthy control subjects by Western-blotting analysis.

RESULTS: 7 of the sixty-one cases and 0 of the controls were sero-positive for BDV-p24 antibody, there was a statistical significant difference between the two groups (11.48% vs 0%; P less than 0.010).

CONCLUSION: Chinese patients with CFS showed sero-positive identifying BDV infection, by comparison, anti.BDV-p24 antibody prevalence in patients was significantly higher than in controls. An etiological association may exist between CFS and BDV infection.

 

Source: Li YJ, Wang DX, Zhang FM, Liu ZD, Yang AY, Ykuta K. Detection of antibody against Borna disease virus-p24 in the plasma of Chinese patients with chronic fatigue syndrome by Western-blot analysis. Zhonghua Shi Yan He Lin Chuang Bing Du Xue Za Zhi. 2003 Dec;17(4):330-3. [Article in Chinese] http://www.ncbi.nlm.nih.gov/pubmed/15340544

 

Electrodermal dissociation of chronic fatigue and depression: evidence for distinct physiological mechanisms

Abstract:

Chronic fatigue syndrome (CFS) has an estimated prevalence between 0.5% and 3%, yet its diagnosis remains contentious. CFS is characterized by subjective symptoms that can be difficult to verify; moreover, depression is a commonly reported CFS complaint, whereas fatigue is a common symptom of depression.

Our primary goal was dissociation of these disorders using psychophysiological methods. As previous research has implicated the autonomic nervous system in CFS, we conducted what we believe to be the first analysis of bilateral electrodermal and skin temperature responses of dextral females in a cross-modal orienting task, to investigate differences between these two patient groups and controls.

A multivariate analysis of variance (MANOVA) examining three measures of electrodermal activity revealed prestimulus tonic skin conductance levels (SCLs) were markedly lower for the CFS group, with no difference between controls and depressives. Concurrent skin temperature levels were higher for the CFS group than the other two groups.

These findings indicate that, despite overtly similar cognitive and symptom profiles, depression and CFS patients can be differentiated with psychophysiological measures. This study adds to the growing body of evidence demonstrating that CFS and depression have distinct neurobiological profiles, consistent with unique aetiologies.

Copyright 2004 Elsevier B.V.

 

Source: Pazderka-Robinson H, Morrison JW, Flor-Henry P. Electrodermal dissociation of chronic fatigue and depression: evidence for distinct physiological mechanisms. Int J Psychophysiol. 2004 Aug;53(3):171-82. http://www.ncbi.nlm.nih.gov/pubmed/15246671

 

Chronic fatigue syndrome: intracellular immune deregulations as a possible etiology for abnormal exercise response

Abstract:

The exacerbation of symptoms after exercise differentiates Chronic fatigue syndrome (CFS) from several other fatigue-associated disorders. Research data point to an abnormal response to exercise in patients with CFS compared to healthy sedentary controls, and to an increasing amount of evidence pointing to severe intracellular immune deregulations in CFS patients. This manuscript explores the hypothetical interactions between these two separately reported observations.

First, it is explained that the deregulation of the 2-5A synthetase/RNase L pathway may be related to a channelopathy, capable of initiating both intracellular hypomagnesaemia in skeletal muscles and transient hypoglycemia. This might explain muscle weakness and the reduction of maximal oxygen uptake, as typically seen in CFS patients.

Second, the activation of the protein kinase R enzyme, a characteristic feature in at least subsets of CFS patients, might account for the observed excessive nitric oxide (NO) production in patients with CFS. Elevated NO is known to induce vasodilation, which may limit CFS patients to increase blood flow during exercise, and may even cause and enhanced postexercise hypotension.

Finally, it is explored how several types of infections, frequently identified in CFS patients, fit into these hypothetical pathophysiological interactions.

 

Source: Nijs J, De Meirleir K, Meeus M, McGregor NR, Englebienne P. Chronic fatigue syndrome: intracellular immune deregulations as a possible etiology for abnormal exercise response. Med Hypotheses. 2004;62(5):759-65. http://www.ncbi.nlm.nih.gov/pubmed/15082102

 

Acetylcholine mediated vasodilatation in the microcirculation of patients with chronic fatigue syndrome

Abstract:

The aetiology of chronic fatigue syndrome (CFS) remains controversial and a number of hypotheses have been put forward to explain it. Research into the condition is hindered by the considerable heterogeneity seen across patients but several reports have highlighted disturbances to cholinergic mechanisms in terms of central nervous system activity, neuromuscular function and autoantibodies to muscarinic cholinergic receptors. This paper examines an altogether separate function for acetylcholine and that is its role as an important and generalized vasodilator.

Most diseases are accompanied by a blunted response to acetylcholine but the opposite is true for CFS. Such sensitivity is normally associated with physical training so the finding in CFS is anomalous and may well be relevant to vascular symptoms that characterise many patients. There are several mechanisms that might lead to ACh endothelial sensitivity in CFS patients and various experiments have been designed to unravel the enigma. These are reported here.

 

Source: Spence VA, Khan F, Kennedy G, Abbot NC, Belch JJ. Acetylcholine mediated vasodilatation in the microcirculation of patients with chronic fatigue syndrome. Prostaglandins Leukot Essent Fatty Acids. 2004 Apr;70(4):403-7. http://www.ncbi.nlm.nih.gov/pubmed/15041034

 

Peripheral cholinergic function in humans with chronic fatigue syndrome, Gulf War syndrome and with illness following organophosphate exposure

Abstract:

In the present study, we have investigated whether the peripheral cholinergic abnormalities that we have reported previously [Spence, Khan and Belch (2000) Am. J. Med. 108, 736-739] in patients with chronic fatigue syndrome (CFS) are also present in those with Gulf War syndrome (GWS) and agricultural workers exposed to organophosphate pesticides, where cholinesterase inhibition is specifically implicated. We also looked at whether these abnormalities might be due to a reduction in the activity of cholinesterase expressed on the vascular endothelium.

We used laser Doppler imaging to measure the forearm skin blood flow responses to iontophoresis of acetylcholine and of methacholine (which is resistant to breakdown by cholinesterase) in patients with CFS, GWS and those with a history of ill health after definite organophosphate exposure, as well as in matched healthy controls.

The response to acetylcholine was significantly higher in patients with CFS than in controls ( P =0.029, repeated-measures ANOVA), but was normal in those with GWS and those exposed to organophosphates. The methacholine response was higher than the acetylcholine response in all patient groups except for those with CFS, where there was no difference between the responses. Although there are many clinical similarities between these three illnesses, our results indicate peripheral cholinergic abnormalities in the vascular endothelium of only patients with CFS, suggesting that this syndrome has a different aetiology, which might involve inhibition of vascular cholinesterase.

 

Source: Khan F, Kennedy G, Spence VA, Newton DJ, Belch JJ. Peripheral cholinergic function in humans with chronic fatigue syndrome, Gulf War syndrome and with illness following organophosphate exposure. Clin Sci (Lond). 2004 Feb;106(2):183-9. http://www.ncbi.nlm.nih.gov/pubmed/14503920

 

The investigation of chronic fatigue syndrome: a case-study of the limitations of inductive inferences and non-falsifiable hypotheses in medical research

Abstract:

Karl Popper’s argument that deductive logic and falsifiable hypotheses are necessary for the growth of scientific knowledge has been controversial. One approach to assess the relevance of his ideas to medical science has been to evaluate examples of successful research. Another approach is to analyze an unsuccessful investigation. The inconclusive search for a unique ‘chronic fatigue syndrome’ offers a well-documented case-study for this analysis. Over the past 130 years, numerous studies have provided clinical and epidemiological data, which have supported competing hypotheses about the etiology of chronic fatigue. However, few hypotheses have been refuted because it has not been possible to establish objective standards of inquiry for a subjective symptom like fatigue. As a result, intensive research efforts have not converged on correct explanations by eliminating erroneous ideas. This unsuccessful investigation illustrates how non-falsifiable hypotheses are insufficient to advance medical knowledge, even when there is an abundance of empirical data.

 

Source: Hyams KC. The investigation of chronic fatigue syndrome: a case-study of the limitations of inductive inferences and non-falsifiable hypotheses in medical research. Med Hypotheses. 2003 May;60(5):760-6. http://www.ncbi.nlm.nih.gov/pubmed/12710915